First you need to cancel the subscription or service you’re being charged for. Review the information and follow the steps in the Apple Support article below.
Request a refund for apps or content that you bought from Apple - Apple Support
Once you’ve requested a refund you can check and see a few days later if it was approved or declined.
Check the status of a refund for apps or content that you bought from Apple - Apple Support
If declined, you can make another request/appeal and determine if approved.
If declined a second time, you’ll need to call or chat with Apple Support.